Abiotrophia defectiva endocarditis of bicuspid aortic valve: a case report

Patients with a bicuspid aortic valve have increased risk of infective endocarditis, but common organisms are not always the culprit. We describe a case of an otherwise healthy young gentleman with bicuspid aortic valve who experienced Abiotrophia defectiva endocarditis. The aim of this case report is to highlight an uncommon cause of endocarditis associated with significant morbidity and mortality in order to improve the care provided by trainees and clinicians.

A 37-year-old male presented with a 1-month history of fever, weight loss, myalgia, and night sweats. On transoesophageal echocardiography, he was found to have a bicuspid aortic valve with large vegetation and severe aortic insufficiency. Blood cultures were positive for A. defectiva. The endocarditis was successfully treated with surgical aortic valve replacement and 6 weeks of antibiotic therapy.

Bicuspid valves are known to have increased susceptibility to endocarditis. The difficulty of isolating A. defectiva typically leads to delayed diagnosis and significant complications. This case is a reminder to have a high degree of suspicion for organisms which are rare and difficult to isolate because prompt recognition and surgical intervention may improve the outcome of care.